Jumpei Yamasaki defeated Taiyo Yamanaka 6-3 6-1 in the M15 Tsukuba 1 q32 on hard. The upset overturned the form book — Taiyo Yamanaka came in ranked #817, leading the head-to-head 2–1. Jumpei Yamasaki narrowed the head-to-head to 2–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2025-09-18 | M25 Takasaki 1 | R16 | hard | Jumpei Yamasaki | 6-2 6-3 |
| 2025-05-23 | M15 Luan 5 | QF | hard | Taiyo Yamanaka | 6-1 6-1 |
| 2024-03-19 | M15 Nishi-Tokyo 1 | Q16 | hard | Taiyo Yamanaka | 7-5 6-3 |
Averages over each player's completed matches in the selected window (5 vs 13). ATP, WTA & Challenger.
Each player's serve crossed against the other's return, converted to expected hold of serve. Recent completed matches, ATP, WTA & Challenger. About